This invention relates to fire-retardant foam for use as thermal insulation, padding in bedding, furniture and other articles.
For safety purposes, to reduce the risk of accidental fires, it is often sought to make building materials and consumer goods fire-proof or retardant. Such fire resistance is usually imparted to certain articles by adding fire-retardant additives, such as a mixture of antimony oxide and a halogenated compound, to the raw materials from which the article is manufactured. However, it has been found that most, if not all, known fire-retardant additives in the proportions in which they are most often employed are unsuitable for use in the manufacture of synthetic foams in that the additives adversely affect the system by which a synthetic foam blend is foamed. For example, it has been found that fire-retardant additives in particle form often adversely alter the nucleation of the foam, causing unwanted variations in the size, number and properties of the foam cells. Similarly, most fire-retardant additives may adversely affect the viscosity and melt strength of polymer constituents of the foam resulting in poor cell structure and cell collapse.
Accordingly, it is a principal object of the present invention to provide a fire-retardant, synthetic foam which overcomes the deficiencies of the prior art.
It is another object of the present invention to provide such a fire-retardant foam wherein properties of the principal polymer constituent thereof are not severely adversely effected by the fire-retardant addition.
It is a further object of the present invention to provide such a fire-retardant foam which may be formed in a variety of profiles for such diverse uses as building insulation, bedding and the like.
It is a further object to provide such a fire-retardant foam characterized by uniform cell properties.
It is another object to provide such a fire-retardant foam wherein fire resistance is achieved without sacrifice in the viscosity and melt strength of a polymer constituent of the foam.
It is yet another object of the present invention to provide such a fire-retardant foam which is of low density and therefore economical to manufacture.